Support passing API keys as environmental variables?

[cboettig]

Problem

I would like to use jupyter-ai in my classroom Jupyterhub without asking students to manually configure API keys. Environmental variables are a commonly used in Jupyterhub and elsewhere to contain such secrets.

Proposed Solution

I can provide my hub with an image already containing a jupyter/jupyter_ai/config.json, but want to be able to write $OPENAI_API_KEY as the key such that the key is loaded from the environmental variable provided via kubernetes secrets rather than hard-coded into the config.

[dlqqq]

Great feedback, thank you for opening an issue! We plan to refactor Jupyter AI's model settings for v3, and this would be an excellent change to include. I'll add it to our v3 milestones. 👍